Maintained load-test results for continuous flight auger piles in south-east England Chalk

Abstract

This paper presents a case study of the results from Roger Bullivant Ltd's testing database from the last 4 years, consisting of eight working load tests and one preliminary test spread across five sites in south-east England. The paper covers the geology of each site and the design of the piles, which was carried out using current industry design practice. The results were analysed to predict the ultimate shaft friction of each pile. As the test results demonstrated that the piles behaved satisfactorily at working load, it is argued that the piles could be seen to be uneconomical. When piles in Chalk are tested, it is common that they rarely deflect to a point where any noticeable failure is deemed to occur. Through a comparison of available published data together with this new data set, a more efficient design is proposed for piles in Chalk with a higher limiting shaft friction value.